Effects of host diet on the tradeoff between mating and immunity in Drosophila melanogaster. Parvin Shahrestani, Brian Lazzaro. Entomology, Cornell University, Ithaca, NY.

   Female Drosophila melanogaster experience post-mating depression of immune defense, suggesting a trade-off between mating or reproduction and immune defense. Both reproduction and immune defense are physiologically demanding and may therefore be mutually limiting as a function of finite energetic reserves in the host. Therefore, the severity of the post-mating immune depression may depend on the condition of the host, which in turn may depend on the diet of the host. I tested the severity of the post-mating immune depression on numerous diets comprised of varying amounts and relative abundances of glucose and protein. The severity of the post-mating immune depression was diet specific, and also depended on the timing of the administration of each diet. Dietary protein seems to be of particular importance, perhaps because of the major amino acid requirements of both egg provisioning and induction of the immune response.